Public cloud applications often need to uniquely identify end-stations connected to private networks. However, standard information (such as an IP address) that may be within a network packet and might otherwise be used to identify the end-station on the private network may be lost when the packet is transferred across a private/public router performing a process such as network address translation (NAT). Accordingly, standard information in a network packet as delivered to a public cloud application may not uniquely identify a source end-station that is on a private network. Other methods for identifying end-stations on private networks are thus needed, but the identification of an end-station should not require the end-station to perform explicit actions or signaling. Otherwise, an identification process may only be operable with end-stations that are specifically modified, upgraded, or built to accommodate identification, and such identification processes may be unable to identify many existing or legacy end-stations.